Key Laboratory of Structure-Based Drugs Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103 Culture Road, Shenhe District, Shenyang, 110016, China.
Department of Pharmacology, Shenyang Pharmaceutical University, 103 Culture Road, Shenhe District, Shenyang, 110016, China.
Eur J Med Chem. 2021 Aug 5;220:113437. doi: 10.1016/j.ejmech.2021.113437. Epub 2021 Apr 20.
Factor XIa, as a blood coagulation enzyme, amplifies the generation of the last enzyme thrombin in the blood coagulation cascade. It was proved that direct inhibition of factor XIa could reduce pathologic thrombus formation without an enhanced risk of bleeding. WSJ-557, a nonpurine imidazole-based xanthine oxidase inhibitor in our previous reports, could delay blood coagulation during its animal experiments, which prompted us to investigate its action mechanism. Subsequently, during the exploration of the action mechanism, it was found that WSJ-557 exhibited weak in vitro factor XIa binding affinity. Under the guide of molecular modeling, we adopted molecular hybridization strategy to develop novel factor XIa inhibitors with WSJ-557 as an initial compound. This led to the identification of the most potent compound 44g with a Ki value of 0.009 μM, which was close to that of BMS-724296 (Ki = 0.0015 μM). Additionally, serine protease selectivity study indicated that compound 44g display a desired selectivity, more 400-fold than those of thrombin, factor VIIa and factor Xa in coagulation cascade. Moreover, enzyme kinetics studies suggested that the representative compound 44g acted as a competitive-type inhibitor for FXIa, and molecular modeling revealed that it could tightly bind to the S1, S1' and S2' pockets of factor XIa. Furthermore, in vivo efficacy in the rabbit arteriovenous shunt model suggested that compound 44g demonstrated dose-dependent antithrombotic efficacy. Therefore, these results supported that compound 44g could be a potential and efficacious agent for the treatment of thrombotic diseases.
XI 因子 a，作为一种血液凝血酶，放大了血液凝血级联反应中最后一种酶凝血酶的产生。事实证明，直接抑制因子 XIa 可以减少病理性血栓形成，而不会增加出血风险。WSJ-557 是我们之前报道的一种非嘌呤咪唑基黄嘌呤氧化酶抑制剂，在动物实验中可以延缓血液凝固，这促使我们研究其作用机制。随后，在探索作用机制的过程中，我们发现 WSJ-557 对体外因子 XIa 的结合亲和力较弱。在分子建模的指导下，我们采用分子杂交策略，以 WSJ-557 为起始化合物开发新型因子 XIa 抑制剂。这导致了最有效的化合物 44g 的鉴定，其 Ki 值为 0.009 μM，接近 BMS-724296（Ki = 0.0015 μM）。此外，丝氨酸蛋白酶选择性研究表明，化合物 44g 表现出所需的选择性，在凝血级联中比凝血酶、因子 VIIa 和因子 Xa 高 400 倍。此外，酶动力学研究表明，代表性化合物 44g 对 FXIa 表现为竞争性抑制剂作用，分子建模表明它可以紧密结合到因子 XIa 的 S1、S1'和 S2'口袋中。此外，在兔动静脉分流模型中的体内疗效研究表明，化合物 44g 表现出剂量依赖性抗血栓形成作用。因此，这些结果支持化合物 44g 可能是治疗血栓性疾病的一种有潜力和有效的药物。
